TY - GEN
T1 - Wind tunnel testing of wings in spin
AU - Ragheb, Adam M.
AU - Selig, Michael S.
N1 - Publisher Copyright:
© 2016, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.
PY - 2016
Y1 - 2016
N2 - Experimental data for use in validation of analytical models of spinning aircraft wings is lacking in the literature, and the field of stall/spin research has recently received new legislative attention. There exists a need for experimental data on wings in a stall/spin regime against which new analytical models may be validated. Experimental wind tunnel tests were conducted in the University of Illinois at Urbana-Champaign low-speed low-turbulence wind tunnel to study the aerodynamics of stalled spinning wings. Wings with symmetric airfoils of t=c ≈ 10% and aspect ratios between 1 and 10 were tested at pitch angles of 30, 60, and 90 deg. Additionally, the effects of airfoil shape were investigated by testing wings with symmetric, flat-bottom, and flat-plate airfoils. Results for Reynolds numbers between 3,000 and 25,000 show that CNvalues increased as the aspect ratio increased over the range of spin parameter, ω, values tested. The effect of wing aspect ratio was observed to decrease as the wing pitch angle was increased within the stall regime to 90 deg. No Reynolds number effects were observed over the range of Reynolds numbers tested, and CNwas observed to follow the square of ω within the range of spin parameter values that may be experienced by an aircraft in a stall/spin situation. For high spin parameter values, a change in concavity was observed, indicating the existence of a maximum CN. A maximum CNvalue, which increases with the aspect ratio, was measured for AR= 1 and AR= 2 wings. Flatbottom airfoils exhibited larger CNvalues than symmetric airfoils, but no significant difference was observed between flat-plate and flat-bottom airfoils.
AB - Experimental data for use in validation of analytical models of spinning aircraft wings is lacking in the literature, and the field of stall/spin research has recently received new legislative attention. There exists a need for experimental data on wings in a stall/spin regime against which new analytical models may be validated. Experimental wind tunnel tests were conducted in the University of Illinois at Urbana-Champaign low-speed low-turbulence wind tunnel to study the aerodynamics of stalled spinning wings. Wings with symmetric airfoils of t=c ≈ 10% and aspect ratios between 1 and 10 were tested at pitch angles of 30, 60, and 90 deg. Additionally, the effects of airfoil shape were investigated by testing wings with symmetric, flat-bottom, and flat-plate airfoils. Results for Reynolds numbers between 3,000 and 25,000 show that CNvalues increased as the aspect ratio increased over the range of spin parameter, ω, values tested. The effect of wing aspect ratio was observed to decrease as the wing pitch angle was increased within the stall regime to 90 deg. No Reynolds number effects were observed over the range of Reynolds numbers tested, and CNwas observed to follow the square of ω within the range of spin parameter values that may be experienced by an aircraft in a stall/spin situation. For high spin parameter values, a change in concavity was observed, indicating the existence of a maximum CN. A maximum CNvalue, which increases with the aspect ratio, was measured for AR= 1 and AR= 2 wings. Flatbottom airfoils exhibited larger CNvalues than symmetric airfoils, but no significant difference was observed between flat-plate and flat-bottom airfoils.
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U2 - 10.2514/6.2016-1073
DO - 10.2514/6.2016-1073
M3 - Conference contribution
AN - SCOPUS:85007495730
SN - 9781624103933
T3 - 54th AIAA Aerospace Sciences Meeting
BT - 54th AIAA Aerospace Sciences Meeting
PB - American Institute of Aeronautics and Astronautics Inc, AIAA
T2 - 54th AIAA Aerospace Sciences Meeting, 2016
Y2 - 4 January 2016 through 8 January 2016
ER -